The invention relates to a combustion-operated working tool, in particular a setting tool for fastening elements, having a housing body, which has a cylindrical recess and a piston chamber communicating therewith for receiving a piston; an impact plate, which is arranged separately spaced opposite to the cylindrical recess facing the housing body and can be moved away from same, and a packing sleeve arranged in the cylindrical recess and projecting therefrom.
DE 199 05 896 A1 discloses a powder-power operated setting tool, which has a first part in the form of a guide cylinder and a second part in the form of an impact plate. Both parts are essentially arranged coaxial to each other and can be displaced parallel to each other in the setting direction. The end zone of the first part facing towards the impact plate has a cartridge bearing, which serves to receive the cartridges. In the setting direction a cartridge chamber communicates with the cartridge bearing and a driver piston is arranged axially displaceable in the chamber. The piston chamber communicates with the cartridge chamber via a connection bore hole.
The impact plate has an axially displaceable mounted bushing on its side facing the guide cylinder. Immediately after firing the cartridge the seal bushing will be urged against the guide cylinder by the accumulating very high pressure if there is a still unused cartridge present in the cartridge bearing and if the impact plate is shifted in towards the guide cylinder, which results in a very reliable sealing of the cartridge bearing in the zone between the guide cylinder and the impact plate.
The packing sleeve is held on the impact plate using an annular discoid elastic membrane. This membrane is fastened securely to the setting side surface of the impact plate. The sealing element has a sealing projection on its setting side surface, which is formed from a peripheral thin-walled projection.